In the proposed work, various schemes for fabricating well-ordered oligonucleotide and polynucleotide films onto gold surfaces will be explored. Emphasis will be placed on the formation of self-assembled monolayers (SAMs) containing DNA molecules or attaching DNA molecules onto preformed SAMs of alkanethiols. These films will be quantified and characterized using a variety of surface and analytical techniques. Five techniques will be employed in an effort to provide a detailed description about the heterogeneous DNA sensor surface: quartz crystal microbalance, atomic force microscope, scanning electrochemical microscope, voltammetry, and electrochemical inductively coupled plasma (ICP)-atomic emission spectrometry ICP-mass spectrometry. These techniques complement one another in terms of studies of DNA immobilization, hybridization intercalation, and film desorption. We intend to integrate the design of the DNA immobilization scheme, the characterization of the sensing surface, and the analytical performance of the resulting sensor of the resulting sensor. Our ultimate objective is to understand certain important factors governing DNA sensor performance (e.g., surface coverage of immobilized DNA, DNA molecular orientation, optimal concentrations of the probe and target for an analysis, and the development of an amenable technique for sensitive and selective detection of nucleic acids) at molecular levels.